Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.10/site-packages/django/db/models/fields/mixins.py: 47%

1from django.core import checks 

2from django.utils.functional import cached_property 

3 

4NOT_PROVIDED = object() 

5 

6 

7class FieldCacheMixin: 

8 """ 

9 An API for working with the model's fields value cache. 

10 

11 Subclasses must set self.cache_name to a unique entry for the cache - 

12 typically the field’s name. 

13 """ 

14 

15 @cached_property 

16 def cache_name(self): 

17 raise NotImplementedError 

18 

19 def get_cached_value(self, instance, default=NOT_PROVIDED): 

20 try: 

21 return instance._state.fields_cache[self.cache_name] 

22 except KeyError: 

23 if default is NOT_PROVIDED: 

24 raise 

25 return default 

26 

27 def is_cached(self, instance): 

28 return self.cache_name in instance._state.fields_cache 

29 

30 def set_cached_value(self, instance, value): 

31 instance._state.fields_cache[self.cache_name] = value 

32 

33 def delete_cached_value(self, instance): 

34 del instance._state.fields_cache[self.cache_name] 

35 

36 

37class CheckFieldDefaultMixin: 

38 _default_hint = ("<valid default>", "<invalid default>") 

39 

40 def _check_default(self): 

41 if ( 

42 self.has_default() 

43 and self.default is not None 

44 and not callable(self.default) 

45 ): 

46 return [ 

47 checks.Warning( 

48 "%s default should be a callable instead of an instance " 

49 "so that it's not shared between all field instances." 

50 % (self.__class__.__name__,), 

51 hint=( 

52 "Use a callable instead, e.g., use `%s` instead of " 

53 "`%s`." % self._default_hint 

54 ), 

55 obj=self, 

56 id="fields.E010", 

57 ) 

58 ] 

59 else: 

60 return [] 

61 

62 def check(self, **kwargs): 

63 errors = super().check(**kwargs) 

64 errors.extend(self._check_default()) 

65 return errors